While the obesity epidemic is spreading at an alarming rate in the modern world especially in the developed countries, there are also a segment of individuals suffering from underweight which get far less attention. Not only will serious underweight create undesirable appearance, it may also result from eating disorders, digestive disorders and depression.
The American Dietetic Association (ADA) defines the ideal body mass index (BMI) as between 20 and 25. Anyone below that range would be considered underweight and those with a BMI from 18.5 and below extremely underweight. The ability for a person to gain or lose weight depends primarily on the person's intake of calories. Calories are found in food. However, the calories in food come in different forms: carbohydrates, fats, and protein. These different forms, known as “macronutrients,” have different effects on the body and its ability to gain weight.
When the person eats more calories than his or her body burns, the extra calories get stored for future use in the form of muscle or fat tissue. Conversely, when the person eats fewer calories than his or her body burns, the person's body taps into stored muscle and fat tissue to get the energy it needs. As a result, a major cause for certain individuals to find gaining weight difficult is a weak appetite or fast metabolism, in addition to eating irregularly due to work, or eating healthy food having low caloric density.
Conventionally, people who tried to gain weight took commercial weight gain shakes as a convenient source of calories. However, high calorie shakes are very filling and may prevent these people from enjoying regular meals by blunting their appetite, causing them to eat little or no food later in the day and resulting in little or no change in body weight.
There are also literatures suggesting that taking multivitamin supplements can improve a person's weight gain. However, such a method is only effective when the person's capability of gaining weight was being affected by certain nutrient deficiencies. People who are not deficient in given nutrients will often find this method ineffective in gaining weight. In fact, most recent research suggests that multivitamin supplementation has no effect on body weight in the general population or that it may actually prevent weight gain. See, e.g., Major, G. C., “Multivitamin and dietary supplements, body weight and appetite: results from a cross-sectional and a randomized double-blind placebo-controlled study” The British journal of nutrition, 5, 1157-1167 (2007); Nachtigal, M. C., “Dietary supplements and weight control in a middle-age population. Journal of alternative and complementary medicine” (New York, N.Y.), 5, 909-915 (2005).
Despite the foregoing efforts to improve weight gain for individuals, conventional methods are not ideally suited for everyone. Accordingly, there exists a need for improved method and formulation for enhancing weight gain which obviates the deficiency of conventional methods.